Re: [PATCH -tip 3/3] locking/pvqspinlock: Robustify init_qspinlock_stat()

[Waiman Long <waiman.long@hpe.com>]

On 04/18/2016 02:31 AM, Davidlohr Bueso wrote:
> Specifically around the debugfs file creation calls,
> I have no idea if they could ever possibly fail, but
> this is core code (debug aside) so lets at least
> check the return value and inform anything fishy.
>
> Signed-off-by: Davidlohr Bueso<dbueso@suse.de>
> ---
>   kernel/locking/qspinlock_stat.h | 14 ++++++++++----
>   1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
> index 72722334237a..ddcd653c942c 100644
> --- a/kernel/locking/qspinlock_stat.h
> +++ b/kernel/locking/qspinlock_stat.h
> @@ -225,12 +225,18 @@ static int __init init_qspinlock_stat(void)
>   	 * performance.
>   	 */
>   	for (i = 0; i<  qstat_num; i++)
> -		debugfs_create_file(qstat_names[i], 0400, d_qstat,
> -				   (void *)(long)i,&fops_qstat);
> +		if (!debugfs_create_file(qstat_names[i], 0400, d_qstat,
> +					 (void *)(long)i,&fops_qstat))
> +			goto fail;
> +
> +	if (!debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
> +				 (void *)(long)qstat_reset_cnts,&fops_qstat))
> +		goto fail;
>
> -	debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
> -			   (void *)(long)qstat_reset_cnts,&fops_qstat);
>   	return 0;
> +fail:
> +	debugfs_remove_recursive(d_qstat);
> +	return 1;
>   }
>   fs_initcall(init_qspinlock_stat);
>

Reviewed-by: Waiman Long <Waiman.Long@hpe.com>

Cheers,
Longman